Watanabe heritable hyperlipidemic (WHHL) rabbits are being examined for evidence of histologic lesions of atherosclerosis. Four age groups are being examined for comparison of lesions at various ages. In each of the four age groups the age at which lesions are first discernible and variations in severity of lesions is examined and categorized. Rabbits of both sexes are being used to determine if any sex differences are present in degree of severity of lesions and age of onset. The serum cholesterol and tryglyceride values are examined also for possible correlation with lesions. The significance of this project lies in the identification of factors relating various serum cholesterol/tryglyceride values with atherosclerotic lesions. By associating lesions with serum values, a profile of the WHHL rabbit will be established.